Suggestion for those who do not know Hebrew: Follow the video with the words in Hebrew/Hebrew translitaration first and when you get a feel for how the song goes, follow it in English to better understand.
And praiseworthy/exalted are His servants, oy, His servants...
Repeat from the top once again
The G-d of Israel's name is not pronounced ---It is forbidden to do so and it is not to be used in vain---. The Holy Name is referred as Hashem/The Name when not in prayers and the word Adon--nai /My L-rd/My Master is pronounced when in prayers.
Words to this song reside in the Machzor for Shavuot - Prayer book for the Feast of Weeks
***The Holy Name was originally used by the Kohen HaGadol/The High Priest in the Holy Temple once a year only, when he entered the Holy of Holies to seek atonement on the HolyDay of Yom Kippur. Today generally, we do not know the correct pronounciation of The Name and we revere Hashem by not seeking to transgress Him in any way.